ATLANTA -- The United States appears headed for its worst year for whooping cough in more than five decades, with the number of cases rising at an epidemic rate that experts say may reflect a problem with the effectiveness of the vaccine.
Nearly 18,000 cases have been reported so far, more than twice the number seen at this point last year, the Centers for Disease Control and Prevention said yesterday. At this pace, the number for the entire year will be the highest since 1959, when 40,000 illnesses were reported.
Nine children have died, and health officials called on adults, especially pregnant women and those who spend time around children, to get a booster shot as soon as possible.
"My biggest concern is for the babies. They're the ones who get hit the hardest," said Mary Selecky, chief of the health department in Washington, one of the states with the biggest outbreaks.
Whooping cough has generally been increasing for years, but this year's spike is startling. The vaccine that had been given to young children for decades was replaced in the late 1990s following concerns about rashes, fevers and other side effects. The new version is considered safer, but may not be as effective long term, said Dr. Anne Schuchat, who oversees the CDC's immunization and respiratory disease programs.
Whooping cough, or pertussis, is a highly contagious disease that can strike people of any age but is most dangerous to children. Its name comes from the sound children make as they gasp for breath.